AbstractA descriptive model of the equipment-replacement decision process is presented which is based upon a survey of companies. Of particular concern was the form of any modelling employed, and the extent of its influence on the actual decision. It appears that, for more costly items, criterion modelling of some type tends to be undertaken but is not influential in the decision process. This contrasts with the less costly items, where the trend is to utilize cost-modelling which subsequently is influential in the decision process. Comments are made upon what appear to be lost modelling opportunities indicated by the survey.